GridWorlds

This project aims to provide some simple grid world environments similar to gym-minigrid for reinforcement learning research in Julia.

Design

A GridWorldBase is used to represent the whole grid world. Inside of it, a 3-D BitArray of size (n_objects, height, width) is used to encode objects in each tile.

While rendering a gridworld in the terminal, we display only one character per grid cell. If multiple objects are present in the same cell location, we go by a priority implied by the indices of the corresponding objects in the objects attribute (which is a tuple, and hence it is ordered) of the GridWorldBase instance.

For example, if the value of the objects attribute is (AGENT, DOOR) and if a cell contains both the agent and a door, then the character corresponding to the AGENT will be displayed.

Usage

using GridWorlds

w = EmptyGridWorld()

w(MOVE_FORWARD)
w(TURN_LEFT)
w(TURN_RIGHT)

# play interactively with Makie.
# you need to manually install Makie with the following command first
# ] add Makie
# first time plot may be slow
using Makie
play(w;file_name="example.gif",frame_rate=5)

TODO

Environment list

• EmptyGridWorld

• FourRooms

• GoToDoor

• DoorKey

• CollectGems

• DynamicObstacles

Needs improvement

• Add test cases
• Benchmark (ensure our implementations do not have significant performance issues)
• A wrapper for ReinforcementLearningBase.jl
• Gif/Video writer